Can some one help with my car?

I have a 2001 buick regal GS that due to some unforeseen circumstances has had to sit since july. I recently received my tax refund and now I am looking to get her going again. I want to do the work i can myself to save money and to use this as a learning experience. Currently three of my tires are flat and I know I will have to take it to an auto mechanic for that(she needed new tires before I let her sit). What can I do to get my car running smoothly or at least what is recomended ? I need to build some confidence in my mechanic skills but I dont even know where to start. The car starts and my transmission was rebuilt two years ago.